Helicobacter pylori is a bacteria that is commonly found in the gastric juices

of the human stomach. This bacteria was found in the 1980’s to be one of the

agents that can cause peptic ulcers, and with treatments from antibiotics, the ulcers

induced from this bacteria have been reduced greatly.

But there are side-effects to the treatment from the antibiotic that eliminates

the Helicobacter pylori. The H. pylori and humans actually have a commensalism,

or a relationship between two organisms, in which one organism doesn’t affect the

other, but benefits from it.

The H. pylori regulates the stomach acids and the hormone ghrelin, which is

a hormone that induces appetite by telling the brain that there is a need to eat. By

eliminating the H. pylori from the stomach, the amount of ghrelin increases, and

the brain interprets this lack of hormone as an increase in hunger when the stomach

is really full.

The hypothesis of this proposed experiment is as follow;

The elimination of H. pylori from the stomach and upper small intestine

deregulates and disturb the production of ghrelin and causes gain

weight.

The experiment that I wish to propose, to confirm this observation, is a

double-blind experiment, an experiment in which all the subjects will be told that

they are receiving the same treatment, and the people handing the medication or

giving the treatment will not know which is the control group or which is the

experimental group. Only the Principal Investigator will know which group is

control (placebo) and which is experimental (drug - in this case antibiotics).

Experimental Design;

Antibiotics will be selected from those that are already known to be effective

in treating (eliminating) H. pylori, have little or no side effect, and are easy

to take (single instead of multiple dose, for example; once a day). There will

be at least 60 (30 for each group) subjects to be tested or a statistically

defined experimental group, all of which must not have been treated for the

H. pylori bacteria in the past, and they must be people who do not use

antibiotics regularly (this will be determined during the subjects interview).

Also, the subjects will be tested (screening test) for the presence of

antibodies for H. pylori. The presence of antibodies, determined by the test,

will tell us that the subjects have (or have had) the bacteria. This is important

because not all humans have the bacteria and to participate in the study all

subjects must have a high probability of carrying the bacteria.

The group will be split into even groups of 30 people (15 men and 15

women). Thirty of the subjects will be given the antibiotic and the other

thirty will be receiving a placebo. The entire group will be told, by the

people handing the medication or placeboes, that the purpose of the

experiment is to test the effectiveness of the antibiotic for eliminating the H.

pylori. After completion of treatment, they should not change their diets or

daily habits.

Subjects will be monitored for weight variations (gain/loss) over a

predefined period of time. Diseases or conditions that may influence weight

(for example, thyroid disease, diabetes, etc will be also monitored).

Summary;

There are two real purposes to this experiment.

Primary: the purpose is to prove whether eliminating H. pylori really affects

weight gain because of the influence that this bacteria may exert in the

production of ghrelin.

Secondary: the mental aspects on the influence of believing that H. pylori

was eliminated could be evaluated. In other words, to see whether thinking

that the H. pylori in your body has been eliminated makes the subjects gain

weight as well or not.